Ok looking into the source code the quickslider doesn't have a class you can apply css to, and adding a class to it will not be easy without editing the source, which we're unfortunately we're unable to support.

The easiest method to achieve the effect you're looking for would be to use the 'features' section and import your slides into there. In the features section each slide is given a unique ID you could target. As far as I'm aware I don't think you'll be able to use css to enable the clickable feature though, you might need to look into a js solution.